This invention relates to the cracking of hydrocarbons and the regeneration of catalyst used in the cracking operation. More particularly, the present invention is concerned with substantially reducing the amount of flue gas products, particularly CO.sub.2 normally found in the off-gas product of a hydrocarbon conversion operation. Essentially, all of the CO.sub.2 originates from the combustion of carbonaceous material in the catalyst regenerator in the form of flue gas and the CO.sub.2 containing flue gas is entrained with catalyst particles transferred from the regeneration zone to the hydrocarbon conversion zone. The CO.sub.2 containing flue gas thus transferred is thereafter recovered along with hydrogen sulfide and gaseous products of hydrocarbon conversion in the unsaturated gas plant amine absorber. Consequently, the hydrogen sulfide thus recovered contains as high as 20 to 30% or more of CO.sub.2. This level of CO.sub.2 is most undesirable and costly to remove. The present invention, therefore, is concerned with a method and means for removing CO.sub.2 rich flue gases entrained with regenerated catalyst passed to a hydrocarbon conversion zone.